On Wednesday, November 9, 2016 1:54:53 PM CET One Thousand Gnomes wrote: > > I think it is a relatively safe assumption that there is only one > > ISA bridge. A lot of old drivers hardcode PIO or memory addresses > > It's not a safe assumption for x86 at least. There are a few systems with > multiple ISA busses particularly older laptops with a docking station. But do they have multiple ISA domains? There is no real harm in supporting it, the (small) downsides I can think of are: - a few extra cycles for the lookup, from possibly walking a linked list to find the correct set of helpers and MMIO addresses - making it too general could invite more people to design hardware around the infrastructure when we really want them to stop adding stuff like this. Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html